fn name(n: u8) -> i32 {
    match n {
        0 => 100,
        1 | 2 => 200,
        3..=5 => 300,
        _ => 400,
    }
}

fn main() {
    let mut i: u8 = 0;
    while i < 8 {
        println!("{} {}", i, name(i));
        i += 1;
    }
}